<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <style>
        div {
            width: 300px;
            height: 200px;
            background-color: pink;
            border-radius: 15px;
        }

        .div {
            width: 300px;
            height: 300px;
            background-color: pink;
            border-radius: 150px;
            /* 50%是宽度和高度的50% */
            /* border-radius: 50%; */
        }

        .div2 {
            width: 600px;
            height: 200px;
            background-color: pink;
            border-radius: 100px;
        }

        .div3 {
            width: 500px;
            height: 500px;
            background-color: pink;
            border-radius: 20px 50px 80px 110px;
        }
    </style>
</head>

<body>
    圆角矩形：
    <br>
    <div></div>
    圆形
    <br>

    <div class="div"></div>
    <br>
    <div class="div2"></div>
    <br>
    <div class="div3"></div>
</body>

</html>